Electrical connectors are used in a variety of applications to interconnect electrical circuits and devices. One such connector is the screw-on, threaded F-type connector (or “F-connector”), which is used on most radio frequency (RF) coaxial cables to interconnect TVs, cable TV decoders, VCR/DVD's, hard disk digital recorders, satellite receivers, and other devices. Male F-type connectors are typically attached to the end of a coaxial cable with the central conductor of the coaxial cable extending therefrom. Male F-type connectors (sometimes called the “male connector” or “male F-connector”) have a standardized design, generally using a 7/16 inch hex nut as a fastener. The nut has a relatively short (e.g., ⅛ to ¼ inch) length and can be grasped by a person's fingers to be tightened or loosened.
In order to maintain a tight electrical connection, and to achieve the intended electrical performance, manufacturers and industry standards often require an F-type connector to be tightened to an attachment structure (with respect to F-connectors, these attachment structures are sometimes called the “female connector” or “female F-connector”) beyond the torque achievable by using only a person's fingers. In the case of cable TV products, for example, the standard has been to tighten the fastener using a 25 in-lb torque (or to tighten another 90-120 degrees from the finger-tight position). Conversely, consumer products, which have weaker attachment structures (such as plastic), require F-type connector fasteners to be wrench-tightened just slightly beyond finger tight.
A person tightening a fastener by hand may only be able to apply 4-5 in-lbs of torque to an F-connector fastener using his/her fingers, whereas 10-25 in-lbs of torque may be required to properly secure an F-connector fastener to an attachment structure. If a person were, however, to use a wrench to tighten the same fastener, in addition to the wrench being bulky and inconvenient, the person runs the risk of over-tightening the fastener and potentially damaging the attachment structure. Applying too little or too much torque can thus result in increases in returns to the manufacturer, customer service calls, and complaints from consumers.
Furthermore, a number of factors, including vibration and thermal cycling, can cause the threaded connection between the male and female connectors to loosen and/or separate, resulting in signal loss or degradation of electrical performance. Similar issues exist with maintaining the connection between other types of male and female connectors, such as RCA connectors, “plug and socket” connectors, and/or blade connectors.